Re: [qemu-s390x] [Qemu-devel] [PATCH v2 3/5] s390x/tcg: Implement VECTOR FIND ELEMENT NOT EQUAL

[David Hildenbrand]

On 28.05.19 15:03, Richard Henderson wrote:
> On 5/28/19 8:02 AM, David Hildenbrand wrote:
>> On 28.05.19 14:55, Richard Henderson wrote:
>>> On 5/24/19 4:33 AM, David Hildenbrand wrote:
>>>> +    /* identify the smaller element */
>>>> +    if (first_inequal < 16) {
>>>> +        uint8_t enr = first_inequal / (1 << es);
>>>> +        uint32_t a = s390_vec_read_element(v2, enr, es);
>>>> +        uint32_t b = s390_vec_read_element(v3, enr, es);
>>>> +
>>>> +        smaller = a < b;
>>>> +    }
>>>> +
>>>> +    if (zs) {
>>>> +        z0 = zero_search(a0, mask);
>>>> +        z1 = zero_search(a1, mask);
>>>> +        first_zero = match_index(z0, z1);
>>>> +    }
>>>> +
>>>> +    s390_vec_write_element64(v1, 0, MIN(first_inequal, first_zero));
>>>> +    s390_vec_write_element64(v1, 1, 0);
>>>> +    if (first_zero == 16 && first_inequal == 16) {
>>>> +        return 3;
>>>> +    } else if (first_zero < first_inequal) {
>>>> +        return 0;
>>>> +    }
>>>> +    return smaller ? 1 : 2;
>>>
>>> Perhaps move the computation of smaller down here where it is used.
>>
>> Wanted to do that but then I realized that I would have to move
>> s390_vec_write_element64() as well, because v1 and v2/v3 could overlap.
> 
> Oh, yes of course.  R-B without any changes.  ;-)
> 

Thanks Richard, will send a pull request to Conny for this part soon.
I'll start getting the vector floating-point instruction into shape this
week. So don't start to relax ;)

Cheers!

> 
> r~
> 


-- 

Thanks,

David / dhildenb